A semi-active suspension embedded controller in a FPGA

This paper explores the applicability of a Piece-Wise Multilinear Fuzzy Inference System (PWM-FIS) to the realization of embedded digital controllers for semi-active suspension systems. The nonlinear controller, obtained by approximation of a modified Skyhook control strategy trough off-line training of the PWM-FIS, has been implemented in a Field Programmable Gate Array (FPGA) following a hardware-software partition methodology. The system comprehends four three-input/one-output parallel fuzzy controllers, thus allowing its application to the control of a complete four-wheel vehicle suspension system. Obtained input/output latency (control signal skew) of the implemented controller is only 90ns which warrants its applicability to any suspension system with high-speed real-time advanced control requirements.